CEL/poor idle...p1222 code...

[BMWManiac]

Here's a little more info. There is a pretty steep hill on my way from work to home and everytime I get on the hill, I just let the car coast in gear. The CEL then comes on and is the only other time besides idle to come on. I know the vac leak is there, but now I'm starting to rethink the damn TPS...

So to sum up the issues:
1) CEL at idle (I can hear the blurps in the exhaust and the idle is pretty rock solid, but you can feel the occassional struggle, then the CEL comes on)
2) CEL when coasting down the hill....perhaps TPS is still out of whack
3) When the car is fully warmed up, it has a tendency (doesn't happen all the time) to stall immediately when giving it gas after turning over the motor (vac leak issue I'm sure)

[jlevie]

The CEL at idle an when coasting is almost certainly caused by intake leaks. Have a smoke test run to find the leaks.

[BMWManiac]

Thanks JLevie....I believe I will address the leaks, if any after I install my refinished intake and go from there.

[BMWManiac]

I think I've finally found and fixed my vac leak.

All this due to replacing my existing intake manifold with another one I acquired....I was going to take it to a mechanic this weekend to smoke test, but so far so good.

On the rear of the intake manifold, there is a triangular shaped piece with three bolts/fasteners and a nipple that receives the vacuum line from the FPR. Well, and I don't know how I didn't notice this before, 2 of the 3 bolts were missing! I removed the piece and didn't find a gasket either. I remember seeing a gasket on realoem.com but when I went there, the gasket (#4) was shown in the pic but not listed????

Quick trip to Autozone for some RTV gasket maker, and I can tell you the drive there with all three bolts in seemed to fix my issue. So far, no CEL where I've gotten them in the past. Once the RTV cures, I'll tighten the bolts and will know tomorrow if I'm all good!

[BMWManiac]

Spoke too soon. I have managed to avoid any CEL while idling and the car idles better. However, the CEL did come on when coasting down a hill, car in gear, no gas, just rolling....and the idle occassionally bounces....

[jlevie]

Until you have a smoke test run you don't know if there are still intake leaks.

[Mr.SWISS]

Just an update. Installed both o rings on the oil return tube so i think that solved my vac leak issue. However, the idle is still high...no more surging though. Had a buddy adjust the throttle/cruise cables and that made it better, even adjusted the screw. However, idle has returned to being above 1k. I think the issue is the TPS...it works, but I installed it facing the throttle opening (parallel). I noted there was room for adjustment of the screws. Should the TPS be angled slightly to the firewall or radiator?

Double fail. That paint mark on there is so the dealer knows if a shade tree went tinkerin away at it. The cables should have a slight slack and NOT be under tension to the butterfly, it should rest on the stop screw.

My guess is Vacuum leak still just not massive like before sans oil drainback tube o rings and either and/or:
TPS is bad, not aligned.
AFM is toasted/out of calibration

[BMWManiac]

Double fail. That paint mark on there is so the dealer knows if a shade tree went tinkerin away at it. The cables should have a slight slack and NOT be under tension to the butterfly, it should rest on the stop screw.

My guess is Vacuum leak still just not massive like before sans oil drainback tube o rings and either and/or:
TPS is bad, not aligned.
AFM is toasted/out of calibration

Why is it a double fail? I work on all my cars, and in order to properly adjust my TPS via the bentley, I had to reset the screw. Also, the cables were removed so I could replace the bushing on the throttle cable, and completely replace my cruise control cable. Lastly, my "buddy" is a BMW mechanic.

I had the engine bay smoked and turns out the intake is sealed. The 4 x rocker shaft plugs were seriously leaking. Replaced them, added RTV, let is cured....no CEL at idle, idle is much better, but all is still not perfect.

When cold, idle surge and the engine will occassionally stall. Also, still get CEL when coasting down a large hill, car in gear.

[BMWManiac]

Another update.....

Seems like another host of problems....

oil pressure light has been coming on. Checked the oil, everything is fine there. I'm guessing the oil pressure sendor is on its way out.

car continues to struggle at first start up in the morning. I know it's cold out, but I figure it shouldn't be like this...maybe I'm wrong. I'm pretty sure after the smoke test, I've resolved my vac leaks....I'm thinking AFM at this point.

Lastly, my car, at 3k rpms, sounds like a damn diesel. I adjusted the valves (cold) and found several out of spec.....went for a drive, no change. I have a 40 min drive today and I may just see if it gets better. Car has sat for about a week, so perhaps I just needs to get warmed up....sound reminds me of the dreaded vanos issue on E36s...which I need to replace on my E36 M3 this weekend....never ends

[88SuperETABD]

Is you car stock?? Make any other changes to the engine? check fuel....you getting proper pressures? Clogged injectors? What year is ur car? Do you have a cold start valve?

You positive your intake leaks are gone??? Have you had it tested after the first time?

I'm in the same boat, cold idle like crap, i just smoke tested and found my valve cover gasket was leaking between the fire wall and the back of the motor. also, check the little plugs from the vacuum lines that go into the TB, put some loctite or something to make sure they dont pop out. That's where my leaks were.

Good luck.

I have parts on the way, I'll let you know my situation after I hopefully fix it :)

[88SuperETABD]

Also, did you CLEAN the SHIT out of your ICV with carb cleaner? Spray that mother down like no other.

[BMWManiac]

I know this is an old threat, but in case nobody saw my build thread, it wasn't due to vac leaks (I did a smoke test, found none), ICV, plugs, injectors.....and I'm not 100% sure, but my motor died shortly after all of is. The rod bearings went, oil pump seized, and I lost all oil pressure....

So, my question is, could these be linked to the CEL or has nothing to do with it?